HttpClient and HttpURLConnection——Android（一）

1.HttpClient

Android SDK中包含了HttpClient，在Android6.0版本直接删除了HttpClient类库，如果仍想使用则解决方法是：

• 如果使用的是eclipse则在libs中加入org.apache.http.legacy.jar 
  这个jar包在：**sdk\platforms\android-23\optional目录中（需要下载android 
  6.0的SDK）
• 如果使用的是android studio则 在相应的module下的build.gradle中加入：

<code class="hljs matlab has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">   android <span class="hljs-cell" style="box-sizing: border-box;">{
       useLibrary <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'org.apache.http.legacy'</span>
        }</span> </code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>

HttpClient的GET请求

首先我们来用DefaultHttpClient类来实例化一个HttpClient，并配置好默认的请求参数：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//创建HttpClient</span>
    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> HttpClient <span class="hljs-title" style="box-sizing: border-box;">createHttpClient</span>() {
        HttpParams mDefaultHttpParams = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicHttpParams();
        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置连接超时</span>
        HttpConnectionParams.setConnectionTimeout(mDefaultHttpParams, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15000</span>);
        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置请求超时</span>
        HttpConnectionParams.setSoTimeout(mDefaultHttpParams, <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15000</span>);
        HttpConnectionParams.setTcpNoDelay(mDefaultHttpParams, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
        HttpProtocolParams.setVersion(mDefaultHttpParams, HttpVersion.HTTP_1_1);
        HttpProtocolParams.setContentCharset(mDefaultHttpParams, HTTP.UTF_8);
        <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//持续握手</span>
        HttpProtocolParams.setUseExpectContinue(mDefaultHttpParams, <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
        HttpClient mHttpClient = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> DefaultHttpClient(mDefaultHttpParams);
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mHttpClient;

    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li></ul>

接下来创建HttpGet和HttpClient，请求网络并得到HttpResponse，并对HttpResponse进行处理：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">useHttpClientGet</span>(String url) {
        HttpGet mHttpGet = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HttpGet(url);
        mHttpGet.addHeader(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Connection"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Keep-Alive"</span>);
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
            HttpClient mHttpClient = createHttpClient();
            HttpResponse mHttpResponse = mHttpClient.execute(mHttpGet);
            HttpEntity mHttpEntity = mHttpResponse.getEntity();
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> code = mHttpResponse.getStatusLine().getStatusCode();
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> != mHttpEntity) {
                InputStream mInputStream = mHttpEntity.getContent();
                String respose = converStreamToString(mInputStream);
                Log.i(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"wangshu"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"请求状态码:"</span> + code + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"\n请求结果:\n"</span> + respose);
                mInputStream.close();
            }
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IOException e) {
            e.printStackTrace();
        }
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>

converStreamToString方法将请求结果转换成String类型：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> String <span class="hljs-title" style="box-sizing: border-box;">converStreamToString</span>(InputStream <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">is</span>) throws IOException {
        BufferedReader reader = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BufferedReader(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> InputStreamReader(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">is</span>));
        StringBuffer sb = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> StringBuffer();
        String line = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">while</span> ((line = reader.readLine()) != <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>) {
            sb.append(line + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"\n"</span>);
        }
        String respose = sb.toString();
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> respose;
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li></ul>

最后我们开启线程访问百度：

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">  <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Thread(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Runnable() {
            <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">run</span>() {
                useHttpClientGet(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://www.baidu.com"</span>);
            }
        }).start();</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>

请求的返回结果，请求状态码为200，结果就是个html页，这里只截取了部分html代码： 

GET请求的参数暴露在URL中，这有些不大妥当，而且URL的长度也有限制：长度在2048字符之内，在HTTP 1.1后URL长度才没有限制。一般情况下POST可以替代GET，接下来我们来看看HttpClient的POST请求。

HttpClient的POST请求

post请求和get类似就是需要配置要传递的参数：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">    <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">useHttpClientPost</span>(String url) {
        HttpPost mHttpPost = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> HttpPost(url);
        mHttpPost.addHeader(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Connection"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Keep-Alive"</span>);
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
            HttpClient mHttpClient = createHttpClient();
            List<NameValuePair> postParams = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ArrayList<>();
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//要传递的参数</span>
            postParams.add(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicNameValuePair(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"username"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"moon"</span>));
            postParams.add(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicNameValuePair(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"password"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"123"</span>));
            mHttpPost.setEntity(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> UrlEncodedFormEntity(postParams));
            HttpResponse mHttpResponse = mHttpClient.execute(mHttpPost);
            HttpEntity mHttpEntity = mHttpResponse.getEntity();
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> code = mHttpResponse.getStatusLine().getStatusCode();
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span> != mHttpEntity) {
                InputStream mInputStream = mHttpEntity.getContent();
                String respose = converStreamToString(mInputStream);
                Log.i(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"wangshu"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"请求状态码:"</span> + code + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"\n请求结果:\n"</span> + respose);
                mInputStream.close();
            }
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IOException e) {
            e.printStackTrace();
        }
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li></ul>

2.HttpURLConnection

Android 2.2版本之前，HttpURLConnection一直存在着一些令人厌烦的bug。比如说对一个可读的InputStream调用close()方法时，就有可能会导致连接池失效了。那么我们通常的解决办法就是直接禁用掉连接池的功能：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"><span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">disableConnectionReuseIfNecessary</span>() {
      <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">// 这是一个2.2版本之前的bug</span>
      <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">if</span> (Integer.parseInt(Build.VERSION.SDK) < Build.VERSION_CODES.FROYO) {
            System.setProperty(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http.keepAlive"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"false"</span>);
      }
}</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>

所以在Android 2.2版本以及之前的版本使用HttpClient是较好的选择，而在Android 2.3版本及以后，HttpURLConnection则是最佳的选择，它的API简单，体积较小，因而非常适用于Android项目。压缩和缓存机制可以有效地减少网络访问的流量，在提升速度和省电方面也起到了较大的作用。另外在Android 6.0版本中，HttpClient库被移除了，HttpURLConnection则是以后我们唯一的选择。

HttpURLConnection的POST请求

因为会了HttpURLConnection的POST请求那GET请求也就会了，所以我这里只举出POST的例子 
首先我们创建一个UrlConnManager类，然后里面提供getHttpURLConnection()方法用于配置默认的参数并返回HttpURLConnection：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">   <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">static</span> HttpURLConnection <span class="hljs-title" style="box-sizing: border-box;">getHttpURLConnection</span>(String url){
        HttpURLConnection mHttpURLConnection=<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
            URL mUrl=<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> URL(url);
            mHttpURLConnection=(HttpURLConnection)mUrl.openConnection();
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置链接超时时间</span>
            mHttpURLConnection.setConnectTimeout(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15000</span>);
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置读取超时时间</span>
            mHttpURLConnection.setReadTimeout(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">15000</span>);
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//设置请求参数</span>
            mHttpURLConnection.setRequestMethod(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"POST"</span>);
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//添加Header</span>
            mHttpURLConnection.setRequestProperty(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Connection"</span>,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Keep-Alive"</span>);
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//接收输入流</span>
            mHttpURLConnection.setDoInput(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//传递参数时需要开启</span>
            mHttpURLConnection.setDoOutput(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">true</span>);
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IOException e) {
            e.printStackTrace();
        }
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">return</span> mHttpURLConnection ;
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li></ul>

因为我们要发送POST请求，所以在UrlConnManager类中再写一个postParams()方法用来组织一下请求参数并将请求参数写入到输出流中：

<code class="hljs avrasm has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> public static void postParams(OutputStream output,List<NameValuePair>paramsList) throws IOException{
       StringBuilder mStringBuilder=new StringBuilder()<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
       for (NameValuePair pair:paramsList){
           if(!TextUtils<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.isEmpty</span>(mStringBuilder)){
               mStringBuilder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.append</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"&"</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
           }
           mStringBuilder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.append</span>(URLEncoder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.encode</span>(pair<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.getName</span>(),<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"UTF-8"</span>))<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
           mStringBuilder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.append</span>(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"="</span>)<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
           mStringBuilder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.append</span>(URLEncoder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.encode</span>(pair<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.getValue</span>(),<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"UTF-8"</span>))<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
       }
       BufferedWriter writer=new BufferedWriter(new OutputStreamWriter(output,<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"UTF-8"</span>))<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
       writer<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.write</span>(mStringBuilder<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.toString</span>())<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
       writer<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.flush</span>()<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
       writer<span class="hljs-preprocessor" style="color: rgb(68, 68, 68); box-sizing: border-box;">.close</span>()<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">;</span>
   }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li></ul>

接下来我们添加请求参数，调用postParams()方法将请求的参数组织好传给HttpURLConnection的输出流，请求连接并处理返回的结果：

<code class="hljs cs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;">   <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">useHttpUrlConnectionPost</span>(String url) {
        InputStream mInputStream = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">null</span>;
        HttpURLConnection mHttpURLConnection = UrlConnManager.getHttpURLConnection(url);
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">try</span> {
            List<NameValuePair> postParams = <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> ArrayList<>();
            <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;">//要传递的参数</span>
            postParams.add(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicNameValuePair(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"username"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"moon"</span>));
            postParams.add(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> BasicNameValuePair(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"password"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"123"</span>));
            UrlConnManager.postParams(mHttpURLConnection.getOutputStream(), postParams);
            mHttpURLConnection.connect();
            mInputStream = mHttpURLConnection.getInputStream();
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">int</span> code = mHttpURLConnection.getResponseCode();
            String respose = converStreamToString(mInputStream);
            Log.i(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"wangshu"</span>, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"请求状态码:"</span> + code + <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"\n请求结果:\n"</span> + respose);
            mInputStream.close();
        } <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">catch</span> (IOException e) {
            e.printStackTrace();
        }
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li></ul>

最后开启线程请求网络：

<code class="hljs java has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">private</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">useHttpUrlConnectionGetThread</span>() {
        <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Thread(<span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">new</span> Runnable() {
            <span class="hljs-annotation" style="color: rgb(155, 133, 157); box-sizing: border-box;">@Override</span>
            <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">public</span> <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">void</span> <span class="hljs-title" style="box-sizing: border-box;">run</span>() {
                useHttpUrlConnectionPost(<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"http://www.baidu.com"</span>);
            }
        }).start();
    }</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>

这里我们仍旧请求百度，看看会发生什么？